This disclosure relates to a control system and fuel injector driver suitable for use with high resistance injectors in cold weather applications.
There are various types of fuel injectors used for different fuel sources, for example. One type of fuel injector is a “low” resistance injector typically used in direct injection gasoline internal combustion engine applications. This injector is driven by a peak and hold fuel injector driver that applies a relatively high current to quickly open the injector using an actuation coil that generates a magnetic field used to open a valve assembly. This current is held for a desired duration to deliver a desired quantity of fuel. Due to the relatively low resistance of injectors, for example, 1-3 ohms, the actuation coil is capable of handling the high current for the duration of the activation.
Fuel injectors for applications such as compressed natural gas (CNG) typically have a relatively “high” resistance, for example, 7-16 ohms. This type of injector is operated using a saturated switch fuel injector driver in which a relatively low current is applied to the actuation coil of the fuel injector. The high resistance injector opens relatively slowly, but operates much cooler due to the lower current.